Development of Rhodnius prolixus (Hemiptera: Reduviidae) under Constant and Cyclic Conditions of Temperature and Humidity

Abstract

Development of Rhodnius prolixus after eclosion until the adult stage was studied at constant temperatures (T), 15, 20, 25, 28, 35°C, and relative humidities (RH), 75, 86 and 97%, and fluctuating (16/ 8 hr) temperatures, T I/II, 15/28°C, 20/25°C, 25/28°C and 25/35°C, and Refeeding was minimal at optimal conditions of T and RH for development. The most refeeding was observed at a constant 35°C. Key words: Rhodnius prolixus -development -temperature -humidityRhodnius prolixus is considered to be one of the most serious vectors of Chagas disease. All five instars including adults are obligatory hematophagous insects and potential vectors of Trypanosoma cruzi. R. prolixus is unable to molt without feeding. Nymphs need to feed at least once ad repletionem to attain the following stage. Moreover, abiotic factors such as temperature and humidity affect insect development. Under laboratory conditions, the temperature range for eclosion and molting of R. prolixus was reported to be between 16-34°C (Gomez-Nuñez & Fernandez 1963). No development was observed at 15°C and 35°C (Galliard 1935, Okasha 1964 insect habitats may differ considerably and vary according to circadian and seasonal patterns. R. prolixus is found mainly in Colombia and Venezuela from 0 to 2,600 m above sea-level, in regions with annual median temperatures from 11 to 29°C and 250 to 2,000 mm annual precipitation (Carcavallo et al. 1977, 1978, Lent & Wygodzinsky 1979. There is little information on the linked impact of cyclic conditions of temperature and humidity on development of Chagas disease vectors. Pippin (1970) showed that development of several triatomine species at unspecified fluctuating temperatures between 18 and 28°C and humidities from 15 up to 65%, was prolonged compared to 25°C and 65% humidity. More detailed investigations on R. prolixus biology in conditions reflecting the insect's natural environment are required to improve control methods. Recently Luz et al. (1998) reported an influence of fluctuating temperature and humidity on starved R. prolixus. In the present study, development of R. prolixus was examined at constant and fluctuating temperatures and humidities within a range of 15 and 35°C, and 75 and 97%. MATERIALS AND METHODSInsect rearing -R. prolixus was reared at 28 ± 1°C and 75 ± 5% humidity with a photoperiod of

Life cycle and reproductive patterns of Triatoma rubrovaria (Blanchard, 1843) (Hemiptera: Reduviidae) under constant and fluctuating conditions of temperature and humidity

“…Higher temperature and lower relative humidity also decrease the development time of eggs and nymphs of T. rubrofasciata, T. melanosoma, R. neglectus and R. robustus 6 11 18 19 . Extremely low humidity can interrupt the insect development 15 , although no influence of humidity on egg development time of R. neglectus was found 18 .…”

“…Most studies on life cycles in Triatominae have been carried out under controlled conditions of temperature and relative humidity, although these factors show daily and seasonal variations in natural habitats 15 .…”

“…Studies on cold resistance showed that T. rubrovaria was the most affected among a number of Triatominae species 5 . However, there is little information concerning the development of Chagas disease vectors under fluctuating temperature and relative humidity 15 .…”

Biology of Triatoma klugi Carcavallo, Jurberg, Lent & Galvão 2001 (Heteroptera: Reduviidae) under Laboratory Conditions: Effects of Distinct Blood Sources and Susceptibility to Trypanosoma cruzi and Trypanosoma rangeli

“…Triatomine mortality and/or development are influenced by several factors such as spontaneous starvation or inappropriate blood-meal intake, temperature, luminosity and humidity (Rocha et al 1994, Luz et al 1999. Development of T. infestans and T. sordida fed on pigeons or in mice showed a higher mortality rate for 1st instar nymphs (Guarneri et al 2000).…”

Comparación del ciclo de vida de Rhodnius colombiensis Moreno, Jurberg & Galvão, 1999 y Rhodnius prolixus Stal, 1872(Hemiptera, Reduviidae, Triatominae) en condiciones de laboratorio

“…Se ha reportado que las temperaturas elevadas, independientemente de la humedad asociada, pueden acelerar el ciclo biológico de la especie; sin embargo, también pueden afectar la sobrevivencia de las colonias, impidiendo su mantenimiento en el laboratorio (37). Por otro lado, se ha observado la existencia de rangos de temperaturas y de humedades relativas propicias para el óptimo desarrollo de los triatominos (38).…”